Hydraulic variable-speed motion transmission



Nov. 15, 1949 G. E. HoLLMANN Erm. 2,488,408

HYDRAULIC VARIABLE SPEED MOTION TRANSMISSICN Filed Nov. 29, 194s 4 Sheets-Sheet 1 .NTI v DAJ.

INVENTORS j Nav. 15, 1949 G. E. HOLLMANN Erm. 2,488,408

HYDRAULIC VARIABLE SPEED MOTION TRANSMISSION Filed Nov. 29, 194s 4 Shets-Sheet 2 N VEN TORS NOV- l5 1949 G. E. HOLLMANN Erm., 2,488,408

HYDRAULIC VARIABLE SPEED MOTION TRANSMISSION Filed Nov. 29, 1946 4 Sheets-Sheet 3 ,4:72 ,INVENTORS Nov. 15, 1949 s. E. HOLLMANN ETAL 2,488,408

HYDRAULIC VARIABLE SPEED MOTION TRANSMISSION Filed Nov. 29. 1946 4 Sheets-Sheet 4 INVENTORS.

Patented Nov. 15, 1949.

OFFICE HYDRAULIC VARIABLE-SPEED MOTION TRANSMISSION George E. Hollmann, Ann Arbor, Mich., and Louis Hollmann, Fort Wayne, Ind.

Application November 29, 1946, Serial No. 712,954

10 Claims. 1

This invention relates to improvements in hydraulic variable speed motion transmissions.

Generally, variable speed transmissions, such as those used in automobiles have speed change gearing in which the gears are shifted out of articulation and moved into engagement with different sets of gears selectively to effect change in the speed ratio between the drive-shaft and the driven shaft, each shifting operation being accompanied by a break in the transmitting force. In such mechanism the various speeds are at definitely fixed ratios, and the changes of speed require a variety of manipulations by the operator which leads to more or less confusion.

An object of the instant invention is to transmit rotary force from a drive-shaft to a driven shaft at gradually varying speed ratios Without shifting of gears or re-arrangement of any of the motion transmitting parts.

Another obJect of the invention is to afford a compact speed change power transmission wherein the articulating gears are maintained in their relative arrangement constantly while variations of the speed are affected.

And a further object of the invention is to provide a transmission constructed so that the speed change between a driveshaft and driven shaft is affected gradually from the minimum to the maximum ratios by manipulation of but one control lever.

Other objects and advantages of the invention appear in the following description.

An illustrative embodiment of the invention is shown in the accompanying drawings, in which:

Fig. 1 is a side elevational view of a structure 35 in which the invention is incorporated, shown in vertical central section;

Fig. 2 is an elevational view showing a transverse section of Fig, 1 on the line A--A thereof;

Fig. 3 is another elevational view showing a 40 transverse section of Fig. 1 on the line B--B thereof;

Fig. 4 is another elevational view of the device shown in Fig. 1 in section on the lines C-C, D-D and E-E thereof, parts being broken away to disclose the relative arrangement of obscure parts;

Fig. 5 is a detail transverse section through the throttle valve and its situs;

Fig. 6 is another detail transverse section of the throttle valve, the rack-shaft by which it is driven and their situs; and f consists of a hollow case I 0 providing an oil bearings I4 is mounted a driven shaft I6. Packing rings I5-I6 are provided on the exterior of the base and opposite end of the case, that encompass the drive and driven shafts respectively, by which leakage of oil from the oil chamber is prevented.

In the rear bearing I4 is mounted an internally toothed gear I1 with which the driven shaft I6 is integral or otherwise secured thereto, and upon the inner end of the drive-shaft I5 is mounted concentrically a pump-head I8, the shaft extending into and keyed in the hub I9 thereof.

An intermediate shaft 2l) is positioned in alinement with and between the drive-shaft and driven shaft, its ends being supported loosely for rotation in the internal gear Il and the pumpwhich is loosely confined a floating internally toothed ring 25, and on the intermediate shaft is keyed an externally toothed pump gear 26 disposed within the bore of said block 23, the pitch diameter thereof being less than that of the floating gear 25 with which the pump gear articulates.

The rear face of the pump-head I8 has thereon a crescent shaped divider 2l that projects into the bore 24 of the cylinder block, the curved inner face thereof being concentric with the pump gear 26 and contacting the points 0f the teeth thereof,'the curved outer face of said divider being concentric with the floating ring 25 and contacting the points of its teeth. Thus, the divider fills in the void in the bore of the cylinder block between the pump gear 26 and the floating ring 25. The rear end of the cylinder block has an intake opening 28 located adjacent one end of the divider .and an outlet opening 29 located adjacent the opposite end thereof, the arrangement being such that when the pump gear and ring are in action the voids between the teeth thereof are filled with transient fluid that is conveyed therein from the intake opening to the outlet, as in well known types of rotary pumps. The outlet of fluid is controlled by a i tubular throttle valve 3 30' one portion of vwhich has an annular series of teeth II, the valve being disposed in a radial bore 32 in the pump-head I8 and loosely confined therein by lock-rings The throttle valve is actuated by a rack-bar 34 that has sliding movement in the pump-head andengagement with the teeth 3l on the valve so that upon endwise movement of the rack-bar the throttle valve is rotated upon its axis.

A valve opening 35, in the plane of the outlet opening29, extends radially through the wall of the valve into the bore 30' thereof and has a lateral tapered extension 36 in the exterior wall of the valve so that upon turning of the valve, more or less of the transient uid entering the Thus, the speed ratio, with respect to the pump and internal gear, is varied accordingly as the whereupon torque of the revolving pump body X is with varying force imparted to the internal gear through the medium. of the planetary gears.

flow through the pump is restrained.

By the transmission thus constructed and operated. rotary movement of the drive-shaft is imparted with varying force to the driven shaft through the medium of the revolving pump and the vplanetary gear mechanism, with gradually varying. speed ratio, under control of throttling mechanism for lstopping or variably retarding Y the pump from functioning as it is bodilyrepump is permitted to escape therefrom out of the internal gear I1, or upon the teeth of the v drive pinion 2l, and the floating ring 25 is ro= tated accordingly by action of the pump-gear 26 causing the oil to circulate through the pump more or less freely accordingly as the throttle valve is open or closed.

Upon the hub ls of the pump head (Fig. 2) is' loosely mounted an axially movable sleeve 31 volved. Variations from the particular construction above disclosed may be resorted to by the exercise -of skill in the art, without departure from the spirit or scope of the invention.

What we claim is:

1. A variable speed transmission comprising a casing having a supply of fluid-therein, a drive shaft journaled through one wall of the casing and a driven shaft journaled through the opposite wall of the casing in axial alignment with the drive shaft, a rotary pump body within the casing mounted on the inner end of the drive shaft for rotation therewith, an intermediate shaft extending -between the respective inner ends of the drive and driven shafts in axial alignment therewith, and journaled at one end within the rotary pump body and at the other end within the driven shaft and interconnected with the having a radial ange 38 that is connected with the rack-bar 34, and is provided with an external annular groove 39 in which pivoted shoes 40 on a yoke 4I extend so that as the yoke is rocked the sleeve is moved axially on the hub I9 causing rotationv of the throttle valve through the medium of the rack-bar. The yoke is secured upon a rock-shaft 42 that ,extends laterally through the case. The ends of the rock-shaft 42 are loosely supported in corresponding bearings 43 in the case, sealing caps 44 being provided to prevent leakage of uid from the oil chamber out through the bearings. One end of the rock,- shaft projects outwardly through the corresponding bearing and is providedv with a lever 42' by which to adjustably move the yoke.

Preferably, the case I0 has a drain plug 45 in its bottom and a dome 46 extending from its top, there being a cover 41 on the dome provided with a vent opening 48.

Operation In utilizing the invention, the drive-shaft I5' is connected with a suitable source of power,

" the driven shaft is connected with mechanism the internal gear I1 and driven shaft remain at rest, the pump idly revolves, and transmission of power fromv the drive-shaft to the driven shaft is substantiallynil. However,whenthethrottlevalve is closed or partially closed', passage of the uid through the pump is restrained more or less,

said pump body, a planetary gearing interposed between the intermediate shaft and the driven shaft and including components mounted on said rotary pump body, a fluid inlet in the pump body and a valve controlled uid outlet in the pump body, means to actuate said valve including means disposed exteriorly of the casing, whereby as the valve is actuated from open to closed position the drive shaft rotates the pump body and planetary gear mechainsm and thus the driven shaft at varying speed ratios dependent upon the amount of fluid ilow through the pump. i y

2. A compact variable speed transmission com,- prising a casing having a supply of fluid therein, a drive shaft journaled through one wall of the casing and terminating within the casing, a driven shaft journaled through the opposite wall of the casing in axial alignment with the drive shaft and likewise terminating within the casing.

a fluid pump body within the casing mounted on the drive shaft for rotation therewith, an

intermediate shaft within the casing in axial A and the gearing interposed between the pump andthe driven shaft and thus the driven shaft at varying speed ratios depending on the quan- V tity of fluid flowing through the pump.

3. A compact variable speed transmission oomprising a stationary casing, axially aligned drive and drivenshafts journaled in opposite walls 'audace of the casing and terminating therewithin, a rotary pump body mounted on the inner end of the drive shaft for mediate shaft within the casing in axial alignment with the drive and driven shafts and Journaled at its opposite ends, respectively, in the pump body and the inner end of the driven shaft and interconnected with the said pump body, an internally toothed ring gear secured to the inner end of the driven shaft for transmitting rotation thereto, a sun gear mounted on the intermediate shaft intermediate the ends thereof and exteriorly of the pump body, planet pinions mounted on stub shafts projecting from the end face of the pump body, said planet pinions meshing with the sun gear and said internally toothed ring gear, said body pump having an inlet and an outlet for the circulation of fluid therethrough, and a valve controlling the said outlet, said valve being disposed within the pump body, and means for actuating the said valve including means positioned exteriorly of the casing whereby, as the valve is actuated from an open to a closed position, the drive shaft imparts roshaft journaled through the opposite wall of the casing terminating therewithin in axial alignment with the drive shaft, a rotary pump body mounted on the inner end of the drive shaft for rotation therewith, an intermediate shaft within the casing disposed between and in axial alignment with the inner ends of the drive and driven shafts, and journaled at one end within the a valve controlled outlet therefor, and means to actuate said valve to regulate the flow of fluid through the pump and thereby the speed of rotation of the driven shaft, said valve actuating means including a lever disposed exteriorly of the casing.

5. A variable speed transmission comprising a casing having a supply of fluid therein, drive and driven shafts and terminating in spaced relation within the casing, a rotary gear pump having a laterally extended hub mounted on the drive shaft for rotation therewith, an intermediate shaft disposed between and in axial alignment with the inner ends of the drive and driven shafts. one end of the intermediate shaft being supported by the rotation therewith, an intercasing having a supply of driven shaft, said pump having an inlet and an outlet, said pump further having a radially extending elongated tubular bore therein constituting a portion of the outlet, an elongated apertured the valve so as to control iiuid flow therethrough. means to rotate said valve including a sleeve slidably mounted on the hub of the pump, a yoke member in engagement with the sleeve and pivotally mounted within the casing. and means disposed exteriorly of the casing to pivotally move said yoke member and thereby slide the said sleeve to rotate the valve, whereby fluid ow through the pump is controlled and thus the rotation imparted to the gearing and the driven shaft is varied in accordance with the degree of uid fiow through the pump.

6. A compact variable speed transmission comprising a casing, a drive shaft journaled through one end thereof, an axially aligned driven shaft journaled through the opposite end thereof, a pump head keyed to the mediate shaft and secured to said pump head, an inlet for the pump cylinder and an outlet therefor extending through the pump head, a valve to control said outlet, gear means within said effect passage of fluid through said pump, said means including a gear keyed to said intermediate shaft, and a planetary transmission comprising a sun gear on the intermediate shaft. an internally toothed ring gear rotating with the driven shaft and planetary pinions interposed between the sun gear and the ring gear and supported on shafts extending from the end face of the pump cylinder, and means to control said valve including means positioned exteriorly of valve is closed, the planetary transmisa unitto drive the driven shaft and when the valve is open relative rotation exists between the pump and the planetary transmission to drive the driven shaft at a reduced rate depending upon the degree of opening of the valve.

7. A variable speed transmission comprising a fluid therein, a drive shaft journaled through one wall of the casing and axially aligned with a driven shaft journaled through the opposite wall thereof, an intermediate shaft disposed within the casing in axial alignment with the drive and driven shafts and freely rotatable relative thereto, a gear pump surrounding said intermediate shaft and including a pump head keyed for rotation with the drive shaft, said pump having a working cylinder surrounding the intermediate shaft, pump gears surrounding said intermediate shaft and disposed about said first mentioned gear, an inlet for passage of fluid-into said pump cylinder, a valve controlled outlet for regulating the discharge of uid from said pump cylinder, a planetary transmisdriven shaft and thereby 'gear keyed cating with sai sion connecting the intermediate shaft with the the driving shaft with the driven ,shaft and valve actuating means including means positioned exteriorly of the casing of uid through the pump whereby when the valve is closed, the relative elements of the pump are locked for rotation as a unit and a direct drive is Ieffected from the drive shaft through the pump mechanism and the planetary transmission tothe driven shaft and as the valveiis opened relative rotation exists between the pump and the planetary transmission to vary the speed of the driven shaft.

8. A variable speed transmission as defined in and by claim 7, wherein the working cylinder of the pump is an enlarged bore formed within the pump eccentric with respect to the drive, driven and intermediate shafts.`

9. A variable speed transmission comprising a stationary casing having a supply of fiuid therein, a drive shaft journaled through one wall of the casing and an axially aligned driven shaft journaled through the opposite wall of the casing, a pump head keyedto the inner end of the drive shaft and rotating therewith, an intermediate shaft freely journaled at one end in the pump head and in its opposite end in the.driven shaft. a pump cylinder surrounding said intermediate shaft and connected to said pump head, an enlarged bore constituting a working chamber formed in the end face of the cylinder block adjacent the end face of the pump head, a pump to said vintermediate shaft and disposed within-said working chamber, a crescent shaped chamber divider extending from the end face of the pump head into the working chamber, an internally toothed fioating ring disposed within the working chamber about the divider and the pump gear, an inlet opening communiworking chamber adjacent one end of the divider, the pump head having a radial bore extending from the outer surface thereof interiorly thereof, .and a lateral passage therein communicating between the radial bore and the working chamber and constituting an outlet therefor, an apertured tubular valve disposed within said radial bore for controlling theilow of fluid through the working chamber, a planetary gearing transmission disposed between said intermediate shaft and said driven shaft, the planet pinions thereof rotating on shafts projecting from the end face of the cylinder block, means to actuate said valve including means positioned exteriorly of the casing, so as the valve is actuated between open and closed position, the passage of fluid therethrough from the working chamber is controlled, thereby varying the speed ratio of the driven shaft with respect to thedrive shaft.

10. A variable speed power transmission comprising a housing having a supply of uid therein, a drive shaft rotatably journaled through a bore in one end of the housing, a driven shaft rotatably journaled through a bore in the opposite end of the housing and in axial alignment with the drive shaft, a pump head circular in cross section and having a laterally extending hub keyed to the inner end of said drive shaft, an internally toothed ring gear within the casing and connected to the inner end of the driven shaft, an intermediate shaft freely journaled at one end in a bore in the driven shaft and at its other axis of the rotation of the pump gear end in the pump headsaid intermediate shaft being in axial alignment with the drive and driven shafts. a pump cylinder block complementary in shape to said pump head and mounted about said intermediate shaft, a bore in the face of said cylinder block adjacent the outer face ofthe pump head and said bore 'constituting a pump,

chamber, a crescent from the oute face of the pump head and projecting within the pump chamber, the outer arcuate face of saiducrescent shaped projection being in spaced relation to the inner wall of said pump chamber, a pump gear keyed to said intermediate shaft and disposed within the pump lchamber, a oating idler ring positioned within the pump chamber and having internal teeth thereon in contact with the outer surface of the crescent shaped projection andof a size to mesh with the'exterior teeth on said pump gear, a laterally extending inlet opening' passing through said pump cylinder block ,and communicating with the bore therein, an elongated radially extending bore.. in said pump head extending from the outer surface inwardly thereof, a lateral passage through said pump head and connecting the said bore with the pump chamber, a vrotatable tubular valve disposed within the radially extending bore in the pump head, said valve having an aperture therethrough adapted to register with the aperture through the pump head that is in communication with the pump chamber, a valve actuating means to rotate said tubular valve so -as to control' the passage of fluid through the pump, a sun gear mounted on the intermediate shaft exteriorly of the outer face of the pump cylinder block, spaced stub shafts projecting from the outer face of said cylinder block and planetary pinions mounted on said stub shafts, said planetary pinions being respectively in mesh with the sun gear and the said internally `toothed ring gear secured to the driven shaft, said valve actuating means including means positioned exteriorly of the casing for controlling the operation of. the transmission so that when the valve is actuated and the aperture therein is out of register with the passage through the pump head and power is applied to the drive shaft, the pump head and cylinder block, the intermediate shaft and the planetary gearing rotate as a unit to drive the driven shaft and as the valve is actuated to allow fluid to pass therethrough relative keyed to the intermediate shaft and the floating ring is permitted which effects rotation of the internally toothed ring gear relative to the cylinder blockthrough the rotation of the sun gear and the planetary pinions thereby transmitting power to the driven shaft at a reduced speed ratio depending upon the amount of fluid owing through the valve.

GEORGE E. HOLLMANN. LOUIS HOLIMANN.

REFERENCES.. C'rrsn l The following references are of record in the le of this patent: s

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Hanson Feb. 25, 1947 shaped projection extending 

